Project Summary/Abstract Alcoholism and alcohol related illnesses put a large strain on society. While therapeutics are available, none are universally effective among the diverse population of treatment seeking individuals. My research is focused on elucidating the role of two delta opioid receptor subtypes (DOR1 and DOR2) in alcohol abuse disorders. Their ability to affect both ethanol consumption and anxiety make these DOR subtypes promising potential novel drug targets to treat alcoholism. So far I have discovered that the DOR subtypes have unique and sometimes opposing effects on ethanol consumption and anxiety. Moreover, I determined that the DOR1's pharmacology may result from an interaction of the DOR with the MOR forming a DOR-MOR heteromer. My research is designed to determine the mechanism behind the unique pharmacology of the DOR subtypes and exploit it to develop novel drugs that can treat alcohol abuse disorders better and with fewer side effects than the currently available medication. One integral part of my research is resolving how chronic ethanol exposure results in an increase in the number of functional DORs. Additionally, I have designed a unique method to identify drugs that selectively interact with receptor heteromers using a high throughput in vitro assay. I intend to further test compounds identified in this assay using mice models of alcoholism, determining their effects on ethanol intake, anxiety, reward and ethanol withdrawal. My ultimate goal is to validate a DOR-subtype as a new target for intervention in alcohol abuse and determine the properties of the most ideal DOR-subtype selective drug as a preclinical lead.